The present invention relates to U-bolt clamp assemblies and more particularly to the construction of a saddle for use in such assemblies.
U-bolt clamps are used for joining together sections of tubing at a connection wherein one piece of tubing is telescoped within another. U-bolt clamps are commonly used to join various components of internal combustion engine exhaust systems, such as exhaust pipes, tail pipes, mufflers, etc. In order to secure the two pieces of tubing relative to one another, the curved portion of the U-bolt and the curved portion of the saddle are placed in contact with the tubing in the area of overlap. Thereafter the saddle is tightened down onto the U-bolt so that the two layers of overlapping tubing deform or crimp into one another. A large amount of force is required to cause the crimping and, hence, both the U-bolt and saddle must have sufficient strength to withstand such forces.
The U-bolts themselves generally have sufficient strength to withstand the forces required to crimp tubing being joined. However, problems have arisen with the saddle portion of the assemblies. Some of the prior art saddle assemblies have tended to twist when force sufficient to crimp tubing has been applied. Prior art U-bolt clamp assemblies have attempted to strengthen saddles in a number of ways. One method has been to double the thickness of the web area, either in full or partially. Another method has been to use flanges extending perpendicularly from the surface of the web sections. The construction of such prior art saddles has generally been complicated due to the requirement of welding of the various components. Examples of various prior art clamps are found in U.S. Pat. Nos. 3,137,053 to Osborn, et al., issued June 16, 1964; 3,192,593 to Osborn, et al., issued July 6, 1965; 3,605,214 to Spotts, et al., issued Sept. 20, 1971; 3,729,782 to Downing, issued May 1, 1973; 3,772,745 to Dowling, et al., issued Nov. 20, 1973; 3,879,815 to Dowling, et al., issued Apr. 29, 1975; 3,919,747 to Offterdinger, issued Nov. 18, 1975; 4,040,152 to Gilgallon, issued Aug. 9, 1977; and 4,056,869 to Eisma, Jr., issued Nov. 8, 1977.
In addition to the strength requirement, simplicity of construction is another important criterion for the saddles. While the prior art saddles may appear to be simple in construction, the requirement of welds can drive up the per unit cost of the saddles.